The system would offer free or discounted transportation based on an algorithm-powered decision-making process involving the user&apos;s current location, the cost of transportation, and the potential profit from a completed sale. The concept is basically a &quot;free ride coupon&quot; and mentioned transportation modes like taxis, trains, buses, or even autonomous vehicles. http://arstechnica.com/gadgets/2014/01/google-patents-ad-powered-taxi-service-that-would-offer-free-rides-to-shoppers/